Transporting system and transporting unit included therein

ABSTRACT

A transporting system includes a first rail including a first region and a second region, the first region being a region where the first rail extends linearly and the second region being a region where the first rail is curved. A second rail includes a third region, separated from the first region, and a fourth region overlapping the second region, wherein the first and second rails merge at a joining location that includes the second region and the fourth region. Optical lines are disposed in the second region and the fourth region, wherein the optical lines are parallel to each other in the fourth region. A first transporting unit travels on the first rail. A second transporting unit travels on the second rail. A first controller controls the traveling of the first and second transporting units using light transmitted or received through the optical lines.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to Korean PatentApplication No. 10-2015-0127766, filed on Sep. 9, 2015, in the KoreanIntellectual Property Office, the disclosure of which is incorporated byreference herein in its entirety.

TECHNICAL FIELD

The present inventive concept relates to a transporting system and atransporting unit included therein.

DISCUSSION OF THE RELATED ART

A transporting system including an automatically controlled transportingunit may be used to load and transport parts or completed productsduring a manufacturing process.

One or more transporting units may move along rails of the transportingsystem installed in a semiconductor manufacturing factory. Two rails ofthe transporting system on which the one or more transporting unitstravel may merge at a merging location. However, when a plurality oftransporting units travel on the two rails, the transporting units maycollide with each other at the merging location.

SUMMARY

According to an exemplary embodiment of the present inventive concept, atransporting system includes a first rail including a first region and asecond region, the first region being a region where the first railextends linearly and the second region being a region where the firstrail is curved. A second rail includes a third region, separated fromthe first region, and a fourth region overlapping the second region,wherein the first and second rails merge at a joining location thatincludes the second region and the fourth region. Optical lines aredisposed in the second region and the fourth region, wherein the opticallines are parallel to each other in the fourth region. A firsttransporting unit travels on the first rail. A second transporting unittravels on the second rail. A first controller controls the traveling ofthe first and second transporting units using light transmitted orreceived through the optical lines.

In an exemplary embodiment of the present inventive concept, the opticallines include first and second optical lines disposed along the thirdregion and separated from each other, and third and fourth optical linesdisposed along the fourth region and separated from each other.

In an exemplary embodiment of the present inventive concept, when thefirst transporting unit enters the second region at a first time and thesecond transporting unit enters the fourth region at a second time laterthan the first time, the first controller supplies the third opticalline with a stop signal.

In an exemplary embodiment of the present inventive concept, thetransporting system further includes a third transporting unit travelingon the first rail, wherein when the third transporting unit enters thesecond region at a third time between the first time and the secondtime, wherein the first controller supplies the third optical line withthe stop signal until the third transporting unit exits the secondregion.

In an exemplary embodiment of the present inventive concept, the firsttransporting unit supplies the first controller with a first entrancesignal through the second optical line when it enters the second region,and the second transporting unit supplies the first controller with asecond entrance signal through the fourth optical line when it entersthe fourth region.

In an exemplary embodiment of the present inventive concept, beforesupplying the first controller with the first and second entrancesignals, the first transporting unit supplies the first controller witha first reference signal to be synchronized with the first controllerand the second transporting unit supplies the first controller with asecond reference signal to be synchronized with the first controller.

In an exemplary embodiment of the present inventive concept, when thefirst and second entrance signals are simultaneously supplied, the firstcontroller simultaneously supplies the first and third optical lineswith a stop signal and controls the first and second transporting unitsto sequentially resume traveling.

In an exemplary embodiment of the present inventive concept, the firstcontroller includes a first interface board connected to the first andsecond optical lines, and a second interface board connected to thethird and fourth optical lines. The first interface board includes afirst transmitting unit supplying the first optical line with an opticalsignal and a first receiving unit receiving an optical signal suppliedfrom the second optical line, and the second interface board includes asecond transmitting unit supplying the third optical line with anoptical signal and a second receiving unit receiving an optical signalsupplied from the fourth optical line.

In an exemplary embodiment of the present inventive concept, the firsttransporting unit includes a second controller disposed in the firsttransporting unit and the second transporting unit includes a thirdcontroller disposed in the second transporting unit.

In an exemplary embodiment of the present inventive concept, the opticallines include a first optical line disposed along the second region anda second optical line disposed along the fourth region, and the secondcontroller supplies the first optical line with a first travel signalwhen the first transporting unit enters the second region.

In an exemplary embodiment of the present inventive concept, when thethird controller enters the fourth region, the third controllerdetermines whether the second transporting unit travels in the fourthregion based on whether the first travel signal is received.

In an exemplary embodiment of the present inventive concept, each of thefirst and second transporting units includes a transmitting unit and areceiving unit which overlaps the optical lines.

In an exemplary embodiment of the present inventive concept, thetransporting system further includes a cover disposed on the opticallines, wherein the cover faces the transmitting unit and the receivingunit of the first transporting unit, wherein the cover reflects a firstoptical signal emitted from the transmitting unit of the firsttransporting unit onto a surface of a first optical line of the opticallines disposed between the cover and the transmitting unit of the firsttransporting unit.

According to an exemplary embodiment of the present inventive concept, atransporting unit includes a support unit supporting a target object. Adriving unit generates a driving force to transport the target object. Areceiving unit receives a first optical signal emitted from a surface ofa first optical line. A transmitting unit emits a second optical signalonto a surface of a second optical line that is spaced apart from thefirst optical line. A controller controls the driving unit using thefirst and second optical signals.

In an exemplary embodiment of the present inventive concept, the firstoptical line and the receiving unit overlap each other, and the secondoptical line and the transmitting unit overlap each other.

According to an exemplary embodiment of the present inventive concept, atransporting system includes a first rail having a first region and asecond region. A second rail has a third region and a fourth region,wherein the second and fourth regions overlap each other, and the firstand second rails merge at a joining location that is within the secondand fourth regions. A first transporting unit is configured to travel onthe first rail. A second transporting unit is configured to travel onthe second rail. A first optical line and a second optical line aredisposed within the second region. A third optical line and a fourthoptical line are disposed within the fourth region. A first controlleris connected to the first, second, third, and fourth optical lines,wherein the first controller is configured to control the traveling ofthe first and second transporting units at the joining location throughthe first, second, third, and fourth optical lines.

In an exemplary embodiment of the present inventive concept, the firstand second transporting units travel through the joining location atdifferent times.

In an exemplary embodiment of the present inventive concept, the firstcontroller communicates with the first transporting unit through thefirst and second optical lines, and the first controller communicateswith the second transporting unit through the third and fourth opticallines.

In an exemplary embodiment of the present inventive concept, when thesecond transporting unit enters the joining location at a first time andthe first transporting unit enters the joining location at a second timelater than the first time, the second transporting unit travels throughthe joining location first, and the first transporting unit is suppliedby the first controller with a stop signal through the first opticalline while the second transporting unit passes through the joininglocation, wherein the first transporting system does not travel throughthe joining location while being supplied with the stop signal.

In an exemplary embodiment of the present inventive concept, after thesecond transporting unit exits the joining location, the firstcontroller stops supplying the first transporting unit with the stopsignal, and the first transporting unit begins traveling through thejoining location.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and aspects of the present inventiveconcept will become more apparent by describing in detail exemplaryembodiments thereof with reference to the following drawings, in which:

FIG. 1 is a diagram illustrating a transporting system according to anexemplary embodiment of the present inventive concept;

FIG. 2 is a perspective view illustrating a transporting unit accordingto an exemplary embodiment of the present inventive concept;

FIG. 3 is a top view illustrating the transporting unit shown in FIG. 2,according to an exemplary embodiment of the present inventive concept;

FIGS. 4 and 5 are sectional views illustrating portions of optical linesin a transporting system according to an exemplary embodiment of thepresent inventive concept;

FIGS. 6 to 8 are diagrams illustrating an operating method of atransporting system according to an exemplary embodiment of the presentinventive concept;

FIGS. 9 and 10 are diagrams illustrating an operating method of atransporting according to an exemplary embodiment of the presentinventive concept;

FIG. 11 is a diagram illustrating an operating method of a transportingaccording to an exemplary embodiment of the present inventive concept;and

FIG. 12 is a diagram illustrating a transporting system according to anexemplary embodiment of the present inventive concept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Aspects and features of the present inventive concept will become moreapparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings. The present inventive conceptmay, however, be embodied in many different forms and should not beconstrued as being limited to the exemplary embodiments thereof setforth herein. The disclosed exemplary embodiments of the presentinventive concept are provided to convey the inventive concept to thoseskilled in the art. In the drawings, the thickness of layers and regionsmay be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, it may bedirectly on or connected to the other element or layer or interveningelements or layers may be present. Like numbers may refer to likeelements throughout the specification. As used herein, the term “and/or”may include any and all combinations of one or more of the associatedlisted items.

The terms “a” and “an” and “the” and similar referents may be construedto cover both the singular and the plural, unless otherwise indicatedherein or the context clearly indicates otherwise.

The present inventive concept may be described with reference toperspective views, cross-sectional views, and/or plan views, in whichexemplary embodiments of the inventive concept are shown. Thus, theprofile view of an exemplary embodiment of the present inventive conceptmay be modified according to manufacturing techniques and/or allowances.Accordingly, the inventive concept may include all changes andmodifications that may occur due to a manufacturing process or a changein the manufacturing process. Thus, regions and the shapes of theregions shown in the drawings are illustrative and do not limit thepresent inventive concept.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as that commonly understood by one of ordinaryskill in the art. Further, all terms defined in generally useddictionaries need not be interpreted in an overly formal sense unlessexpressly so stated herein.

Hereinafter, a transporting system, according to an exemplary embodimentof the present inventive concept, will be described with reference toFIG. 1.

FIG. 1 is a diagram illustrating a transporting system according to anexemplary embodiment of the present inventive concept.

Referring to FIG. 1, the transporting system 1 includes a first rail101, a second rail 102, first to fourth optical lines 21 to 24, firstand second transporting units 51 and 52 and a controller 120.

The first and second rails 101 and 102 may be merged so an object beingtransported on the first and second rails 101 and 102 may continue to betransported through a rail that results from merging the first andsecond rails 101 and 102.

The first rail 101 may include a first region 11 and a second region 12separated from each other. The second rail 102 may include a thirdregion 13 and a fourth region 14 separated from each other. The firstregion 11 may be a region of the first rail 101 that extends linearly.The second region 12 may be a region of the first rail 101 in which thefirst rail 101 extends in a predetermined curvature. For example,according to an exemplary embodiment of the present inventive concept,the first rail 101 is curved in the second region 12.

The first rail 101 and the second rail 102 may be disposed to join eachother at a joining area. The joining area may be referred to as ajoining location. The joining area is a region where the separatelyextending first and second rails 101 and 102 merge and includes aportion of the second region 12 of the first rail 101 and a portion ofthe fourth region 14 of the second rail 102. For example, a plurality ofrails may merge in the joining area to then extend as a single rail. Inan exemplary embodiment of the present inventive concept, the first andsecond rails 101 and 102 merge in the joining area to extend as a singlerail.

The first rail 101 and the second rail 102 may include the first region11 and the third region 13, respectively, which are separate from eachother.

In addition, the first rail 101 and the second rail 102 may be disposedto join each other at the second region 12 and the fourth region 14. Forexample, a portion of the second region 12 of the first rail 101 and aportion of the fourth region 14 of the second rail 102 may overlap eachother.

The first transporting unit 51 and the second transporting unit 52 maytravel on the first rail 101 and the second rail 102, respectively.Configurations of the first and second transporting units 51 and 52 willbe described in detail below.

The first to fourth optical lines 21 to 24 may be disposed on the firstrail 101 and the second rail 102. In an exemplary embodiment of thepresent inventive concept, the first to fourth optical lines 21 to 24may be disposed along the joining area of the first and second rails 101and 102 without being disposed in other regions.

For example, the first and second optical lines 21 and 22 may bedisposed to extend in the second region 12 of the first rail 101 withoutbeing disposed in the first region 11. In addition, the third and fourthoptical lines 23 and 24 may be disposed to extend in the fourth region14 of the second rail 102 without being disposed in the third region 12.In an exemplary embodiment of the present inventive concept, a firstportion of the first and second optical lines 21 and 22, correspondingto the second region 12, may be curved. The curved first and secondoptical lines 21 and 22 may be equally distant from each other. Inaddition, a second portion of the first and second optical lines 21 and22, corresponding to the second region 12, may be straight, and thestraight first and second optical lines 21 and 22 may be parallel toeach other. In an exemplary embodiment of the present inventive concept,the third and fourth optical lines 23 and 24 may be straight andparallel to each other.

When the first and second optical lines 21 and 22 are disposed to extendin the second region 12 of the first rail 101 and the first transportingunit 51 enters the joining area of the first rail 101 and the secondrail 102, the first transporting unit 51 may use the first and secondoptical lines 21 and 22 to communicate with the controller 120. Forexample, when the first transporting unit 51 exits the first region 11to then enter the second region 12, a transceiving unit 31 of the firsttransporting unit 51 may start communication with the controller 120through the first and second optical lines 21 and 22.

When the first transporting unit 51 exits the second region 12 of thefirst rail 101, the first transporting unit 51 is disconnected from thefirst and second optical lines 21 and 22. Accordingly, communicationbetween the first transporting unit 51 and the controller 120 throughthe first and second optical lines 21 and 22 may be terminated.

When the third and fourth optical lines 23 and 24 are disposed in thefourth region 14 of the second rail 102 and the second transporting unit52 enters the joining area of the first and second rails 101 and 102,the second transporting unit 52 may use the third and fourth opticallines 23 and 24 to communicate with the controller 120. Like the firsttransporting unit 51, when the second transporting unit 52 enters thefourth region 14 of the second rail 102, the second transporting unit 52may start communication with the controller 120 using the third andfourth optical lines 23 and 24.

In addition, communication between the second transporting unit 52 andthe controller 120, using the third and fourth optical lines 23 and 24,may be terminated when the second transporting unit 52 exits the fourthregion 14.

As described above, since the first to fourth optical lines 21 to 24 aredisposed on the joining area of the first and second rails 101 and 102,for example, the second and fourth regions 12 and 14, the first andsecond transporting units 51 and 52 may communicate with the controller120 using the first to fourth optical lines 21 to 24 in the joining areaof the first and second rails 101 and 102. Therefore, the controller 120may determine whether the first and second transporting units 51 and 52enter or exit the joining area based on communication states of thefirst and second transporting units 51 and 52.

In addition, when the first to fourth optical lines 21 to 24 aredisposed on the second and fourth regions 12 and 14, but the first tofourth optical lines 21 to 24 are not disposed throughout the entirearea of the transporting system 1 (e.g., the first to fourth opticallines 21 to 24 are disposed on the second and fourth regions 12 and 14but the first to fourth optical lines 21 to 24 are not disposed on thefirst and third regions 11 and 13), system complexity and maintenanceand repair difficulty may be reduced.

Optical communications between the first and second transporting units51 and 52 and the controller 120 using the first to fourth optical lines21 to 24 will be described in detail below.

The controller 120 may include first and second interface boards 131 and132. The first interface board 131 may include a first transmitting unit141 and a first receiving unit 142. The first interface board 131connected to the controller 120 may communicate with the firsttransporting unit 51 using the first transmitting unit 141 and the firstreceiving unit 142.

In addition, the second interface board 132 may communicate with thesecond transporting unit 52 through a second transmitting unit 143 and asecond receiving unit 144 connected to the third and fourth opticallines 23 and 24.

FIG. 2 is a perspective view of a transporting unit according to anexemplary embodiment of the present inventive concept. FIG. 3 is a topview of the transporting unit shown in FIG. 2, according to an exemplaryembodiment of the present inventive concept.

Referring to FIGS. 2 and 3, the first transporting unit 51 may include asupport unit 151 supporting a target object, a driving unit 152generating a driving force to transport the target object, and thetransceiving unit 31 optically communicating with the controller 120through the first and second optical lines 21 and 22.

The shape of the first transporting unit 51 shown in FIG. 2 is providedonly for illustration, but aspects of the present inventive concept arenot limited thereto. For example, since the driving unit 152 is disposedunder the first transporting unit 51 shown in FIG. 2, the firsttransporting unit 51 is suspended from the first rail 101 and travels insuch a state.

However, in an exemplary embodiment of the present inventive concept,the driving unit 152 may be disposed on the first transporting unit 51,and the first transporting unit 51 may travel on the first rail 101.

The target object transported by the first transporting unit 51 may beloaded on the support unit 151 and is supported by the support unit 151.

The transceiving unit 31, which is positioned to vertically overlap thefirst and second optical lines 21 and 22, receives an optical signalemitted from the first optical line 21 and emits an optical signal intothe second optical line 22.

The first to fourth optical lines 21 to 24 may be optical lines havingside emitting characteristics. For example, side surfaces or an exteriorsurface of each of the first to fourth optical lines 21 to 24 may betransparent and may have light-permeating characteristics. Thus, opticalsignals may be read from exterior surfaces of the first to fourthoptical lines 21 to 24, respectively, and optical signals may be enteredinto the first to fourth optical lines 21 to 24 through the exteriorsurfaces of the first to fourth optical lines 21 to 24.

The first to fourth optical lines 21 to 24 may be formed of a collectionof optical fibers having side emitting characteristics, but aspects ofthe present inventive concept are not limited thereto. The first tofourth optical lines 21 to 24 may constitute a single cable having atransparent cylindrical exterior surface.

The first to fourth optical lines 21 to 24 may be made of a plasticmaterial having good bendability. For example, the first and secondrails 101 and 102 may be disposed in the first to fourth regions 11 to14 in curved shapes. Therefore, to curve the first to fourth opticallines 21 to 24 along the curved first and second rails 101 and 102, thefirst to fourth optical lines 21 to 24 may include a material that canbe deformed. For example, the first to fourth optical lines 21 to 24 mayinclude a flexible material.

Since the first to fourth optical lines 21 to 24 use side emittingcharacteristics for transmitting information, optical signalstransmitted through the first to fourth optical lines 21 to 24 may haveweaker intensities toward their terminals. Therefore, the first tofourth optical lines 21 to 24 may include optical repeaters for relayingoptical signals between repeater sections of the first to fourth opticallines 21 to 24.

FIGS. 4 and 5 are sectional views illustrating portions of optical linesin a transporting system according to an exemplary embodiment of thepresent inventive concept.

Referring to FIGS. 4 and 5, in an exemplary embodiment of the presentinventive concept, the first transporting unit 51 performs opticalcommunication using the first and second optical lines 21 and 22 basedon side emitting characteristics of the first and second optical lines21 and 22. For example, as shown in FIGS. 4 and 5, the followingdescription will be made on the assumption that the transceiving unit 31of the first transporting unit 51 is disposed under the first and secondoptical lines 21 and 22.

For example, when an optical signal is incident to the first opticalline 21 from the first transmitting unit 141 of the controller 120, someportions a, b and c of the optical signal are totally reflected on theinside of the first optical line 21, and the remaining portions d and eof the optical signal may be emitted by lower and upper side surfaces Aand B of the first optical line 21, respectively.

The optical signal (e.g., the portion e of the optical sign) emitted tothe lower side surface A of the first optical line 21 may be received bythe transceiving unit 31 of the first transporting unit 51. For example,the portion e of the optical signal emitted to the lower side surface Aof the first optical line 21 may be received by a receiving unit 33included in the transceiving unit 31.

In an exemplary embodiment of the present inventive concept, thereceiving unit 33 may include a photo diode, but aspects of the presentinventive concept are not limited thereto.

The transmitting of the optical signal to the controller 120 through thesecond optical line 22 may be performed by a transmitting unit 34included in the transceiving unit 31. The transmitting unit 34 emits theoptical signal onto a lower side surface of the second optical line 22.

The optical signal emitted by the transmitting unit 34 is incident to alower side surface of the second optical line 22 and enters the secondoptical line 22 through the lower side surface of the second opticalline 22. Having entered the second optical line 22, the optical signalmay be transmitted through the second optical line 22 to the firstreceiving unit 142 of the controller 120.

Since the side surfaces of the first and second optical lines 21 and 22are both made of light-permeating materials, the light emitted to theside surface of the first optical line 21 may enter the first opticalline 21 and travel through the first optical line 21 toward the upperside surface B of the first optical line 21.

In addition, the optical signal emitted by the transmitting unit 34 ontothe lower side surface of the second optical line 22 may interfere withthe first optical line 21 or the receiving unit 33. Therefore, in orderto avoid unwanted transmission of the optical signal, a cover 35 may beinstalled on the first and second optical lines 21 and 22.

The cover 35 covering top portions of the first and second optical lines21 and 22 may prevent the optical signal from being dispersed orinterfered in an unwanted direction. For example, internal sidewalls 36and 37 of the cover 35, facing the cover 35 and the first and secondoptical lines 21 and 22, include reflective materials to reflect thelight emitted from the upper side surfaces B of the first and secondoptical lines 21 and 22, respectively, back into the first and secondoptical lines 21 and 22.

Therefore, a portion of the optical signal emitted from the firstoptical line 21 is reflected by the internal sidewall 36 of the cover 35back into the first optical line 21. For example, the portion of theoptical signal reflected by the internal sidewall 36 of the cover 35 maybe directed toward the lower side surface A of the first optical line 21and enter the first optical line 21. Accordingly, a sensitivity of theoptical signal received by the receiving unit 33 may be increased. Inaddition, the cover 35 may prevent the optical signal emitted from thefirst optical line 21 from causing interference to the second opticalline 22.

A portion of the optical signal emitted from the transmitting unit 34 isreflected by the internal sidewall 37 of the cover 35 back into thesecond optical line 22. For example, the portion of the optical signalreflected by the internal sidewall 37 of the cover 35 may be directedtoward the lower side surface A of the second optical line 22 and enterthe second optical line 22. In addition, the cover 35 may prevent theoptical signal emitted by the transmitting unit 34 toward the secondoptical line 22 from causing interference to the first optical line 21.

The first transmitting unit 141 may include an emitting diode emittinglight into the first optical line 21. In addition, the first receivingunit 142 may include a photo diode for detecting the light that passesthrough the second optical line 22.

Referring again to FIGS. 2 and 3, the first transporting unit 51 mayinclude a controller 200. The controller 200 may control traveling ofthe first transporting unit 51 based on the transmitting/receivingresults of the transceiving unit 31 of the first transporting unit 51using the first to fourth optical lines 21 to 24.

FIGS. 6 to 8 are diagrams illustrating an operating method of atransporting system according to an exemplary embodiment of the presentinventive concept.

Referring to FIG. 6, the first transporting unit 51 traveling on thefirst rail 101 enters a joining area of the first rail 101 and thesecond rail 102, for example, the second region 12. At this time, thesecond transporting unit 52 is disposed in the third region 13, forexample, the second transporting unit 52 has yet to enter the joiningarea of the first rail 101 and the second rail 102.

When the first transporting unit 51 enters the second region 12,communication between the first transporting unit 51 and the controller120 may be started as described below.

When the first transporting unit 51 enters the second region 12, thetransceiving unit 31 is disposed so as to overlap with the first andsecond optical lines 21 and 22. The receiving unit 33 may receive afirst signal 61 from the first transmitting unit 141 of the controller120. The transmitting of the first signal 61 by the first transmittingunit 141 of the controller 120 may be performed through the firstoptical line 21.

The first signal 61 is a signal for starting synchronization between thefirst transporting unit 51 and the controller 120 and may include areference signal. The synchronization may indicate that communicationperiods of the first transporting unit 51 and the controller 120 aremade to coincide with each other to start the communicationtherebetween.

When the communication between the controller 120 and the firsttransporting unit 51 using the reference signal is completed, thecontroller 120 and the first transporting unit 51 are connected to eachother and a first travel signal 62 is transmitted from the firsttransporting unit 51 to the receiving unit 142 of the controller 120.The transmitting of the first travel signal 62 to the receiving unit 142of the controller 120 by the first transporting unit 51 may be performedby transmitting the first travel signal 62 through the second opticalline 22. The first travel signal 62 may also be referred to as a firstentrance signal.

As described above, the communication between the first transportingunit 51 and the controller 120 using the first and second optical lines21 and 22 may be performed using side or exterior surface emissioncharacteristics of the first and second optical lines 21 and 22.

Since the second transporting unit 52 is yet to enter the joining areaof the first rail 101 and the second rail 102 and is still traveling onthe third region 13, communication between the second transporting unit52 and the controller 120 has not started.

Referring to FIG. 7, the second transporting unit 52 enters the joiningarea of the first rail 101 and the second rail 102 later than the firsttransporting unit 51. For example, the second transporting unit 52 mayexit the third region 13 to then enter the fourth region 14.

Since a fourth transceiving unit 134 of the second transporting unit 52is disposed so as to overlap with the third and fourth optical lines 23and 24, the communication between the second transporting unit 52 andthe controller 120 may be started.

When the second transporting unit 52 enters the fourth region 14, areceiving unit of the fourth transceiving unit 134 of the secondtransporting unit 52 may receive a second signal 63 through the thirdoptical line 23. The second signal 63 may be a signal for startingsynchronization between the second transporting unit 52 and thecontroller 120 and may include a reference signal. The synchronizationmay indicate that communication periods of the second transporting unit52 and the controller 120 are made to coincide with each other to startthe communication therebetween.

When the communication between the controller 120 and the secondtransporting unit 52 using the reference signal is completed, thecontroller 120 and the second transporting unit 52 are connected to eachother and a second travel signal 65 may be transmitted to the secondreceiving unit 144 of the controller 120 through the fourth optical line24. The second travel signal 65 may also be referred to as a secondentrance signal.

A second transmitting unit 143 of the controller 120 may supply thesecond transporting unit 52 with the second signal 63 through the thirdoptical line 23. Here, the second signal 63 supplied from the secondtransmitting unit 143 of the controller 120 may be the first travelsignal 62 supplied from the first transporting unit 51. For example, thefirst travel signal 62 supplied from the first transporting unit 51 maybe supplied to the second transporting unit 52 without being separatelyprocessed.

When the second transporting unit 52 is supplied with the second signal63 from the controller 120, it may recognize the supplied second signal63 as a stop signal and the second transporting unit 52 is stopped fromtraveling on the second rail 102.

When the second transporting unit 52 enters the joining area of thefirst rail 101 and the second rail 102 in a state in which the travelingof the second transporting unit 52 on the second rail 102 is notcontrolled, the second transporting unit 52 may collide with the firsttransporting unit 51 which has entered the joining area earlier than thesecond transporting unit 52.

Therefore, the controller 120 recognizes that the first transportingunit 51 enters the joining area of the first rail 101 and the secondrail 102 and transfers the travel signal of the first transporting unit51 to the second transporting unit 52 to make the second transportingunit 52 stop traveling. Traveling stability between the first and secondtransporting units 51 and 52 may be increased under the control of thecontroller 120.

Referring to FIG. 8, the first transporting unit 51 continues to travelalong the joining area of the first rail 101 and the second rail 102until it exits the joining area. Therefore, when the first transportingunit 51 exits the joining area of the first rail 101 and the second rail102, the first transporting unit 51 stops supplying the first travelsignal 62 to the controller 120. Accordingly, the controller 120 maystop supplying the stop signal 63 to the second transporting unit 52.

When the supplying of the stop signal 63 to the second transporting unit52 is stopped, traveling of the second transporting unit 52 on thesecond rail 102 may be resumed. When the second transporting unit 52enters and travels along the joining area of the first rail 101 and thesecond rail 102, the second travel signal 65 may be transmitted to thefourth optical line 24. When another transporting unit enters the secondregion 12, the second transporting unit 52 may be notified to avoidcollision.

The driving unit (e.g., the driving unit 152 shown in FIG. 2) of each ofthe first and second transporting units 51 and 52 may be controlledusing the travel signal and the stop signal transmitted/received by thetransceiving units 31, 32, 133 and 134. The controlling of the drivingunit 152 may be performed by the controller (e.g., the controller 200shown in FIG. 2) of the first and second transporting units 51 and 52.The driving unit (e.g., the driving unit 152 shown in FIG. 2) of each ofthe first and second transporting units 51 and 52 may control thetraveling of the first and second transporting units 51 and 52 on thefirst and second rails 101 and 102.

According to an exemplary embodiment of the present invention, thesecond transporting unit 52 may enter the joining area of the first rail101 and the second rail 102 before the first transporting unit 51. Inthis case, after synchronizing the second signal 63 with the controller120, the second transporting unit may start communication with thecontroller 120, transmit the second travel 65 to the controller 120, andtravel through the joining area of the first rail 101 and the secondrail 102. When the first transporting unit 51 enters the joining area ofthe first rail 101 and the second rail 102, the first transporting unit51 may synchronize the first signal 61 with the controller 120 to begincommunicating with the controller 120. In this case the first signal 61supplied to the first transmitting unit 51 may be the second travelsignal 65.

When the first transporting unit 51 is supplied with the first signal 61from the controller 120, it may recognize the supplied first signal 61as a stop signal and the first transporting unit 51 is stopped fromtraveling on the first rail 101.

The transporting system 1 controls traveling of the first and secondtransporting units 51 and 52 through the first to fourth optical lines21 to 24 disposed on the joining area of the first rail 101 and thesecond rail 102. Accordingly, positions of the first and secondtransporting units 51 and 52 may be identified and traveling of thefirst and second transporting units 51 and 52 may be controlledthroughout the entire joining area. Therefore, the operating reliabilityof the transporting system 1 may be increased.

FIGS. 9 and 10 are diagrams illustrating an operating method of atransporting according to an exemplary embodiment of the presentinventive concept.

Referring to FIG. 9, the first transporting unit 51 and the secondtransporting unit 52 may simultaneously enter the joining area of thefirst rail 101 and the second rail 102. For example, the firsttransporting unit 51 may enter the second region 12 at the same timethat the second transporting unit 52 enters the fourth region 14.

The first and second transporting units 51 and 52 may receive first andsecond signals 61 and 63 from the first optical line 21 and the thirdoptical line 23, respectively. Here, the first and second signals 61 and63 may be reference signals for synchronizing the controller 120 withthe first and second transporting units 51 and 52.

After being supplied with the first signal 61, the first transportingunit 51 may supply a first travel signal 62. At the same time, thesecond transporting unit 52 may supply the controller 120 with a secondtravel signal 65.

When the controller 120 is simultaneously supplied with the first andsecond travel signals 62 and 65, it may recognize that the first andsecond transporting units 51 and 52 simultaneously entered the joiningarea of the first rail 101 and the second rail 102, and may supply thefirst and second transporting units 51 and 52 with a stop signal. Thefirst and second transporting units 51 and 52 may stop travelingimmediately after receiving the stop signal.

Referring to FIG. 10, in order to resume the traveling of the first andsecond transporting units 51 and 52, the controller 120 may stopsupplying the first transporting unit 51 with a stop signal 61.Accordingly, the first transporting unit 51 may resume traveling on thefirst rail 101. At the same time, the first transporting unit 51 maysupply the second optical line 22 with a first travel signal 62.

Until the first transporting unit 51 completes traveling of the joiningarea of the first rail 101 and the second rail 102, the controller 120may continue to supply the second transporting unit 52 with a stopsignal 161. Therefore, the second transporting unit 52 may stoptraveling until the first transporting unit 51 exits the second region12.

FIG. 11 is a diagram illustrating an operating method of a transportingaccording to an exemplary embodiment of the present inventive concept.

Referring to FIG. 11, the first transporting unit 51 may first enter thejoining area of the first rail 101 and the second rail 102 and a thirdtransporting unit 53 may then enter the joining area. For example, thefirst and third transporting units 51 and 53 may enter the joining areaof the first rail 101 and the second rail 102 before the secondtransporting unit 52.

The first transporting unit 51 and the third transporting units 51 and53 are supplied with a first signal 61 from the controller 120 and maytravel on a first rail 101. Here, the first transporting unit 51 havingfirst entered the second region 12 supplies a first travel signal 62.However, the third transporting unit 53 may not supply a separate travelsignal because the second optical line 22 is used intransmitting/receiving the first travel signal 62.

At the same time when the second transporting unit 52 enters the fourthregion 14, the second transporting unit 52 may be supplied with a secondsignal 63 from the controller 120. The second signal 63 may be the firsttravel signal 62 supplied from the first transporting unit 51, and thesecond transporting unit 52 supplied with the second signal 63 may stoptraveling on the second rail 102. When the first transporting unit 51exits the second region 12, the third transporting unit 53 is suppliedwith the first signal 61 from the controller 120 and supplies thecontroller 120 with the first travel signal 62. The second transportingunit 52 may be supplied with the second signal 63, which may be thefirst travel signal 62 supplied from the third transporting unit 53, toremain stopped. When the third transporting unit 53 exits the secondregion 12, the controller 120 may stop transmitting the second signal 63to the second transporting unit 52 so the second transporting unit 52may start traveling on the fourth region 14 of the second rail 102. Forexample, the second transmitting unit 143 supplies the third opticalline 23 with the second signal 63 until the third transporting unit 53exits the second region 12.

FIG. 12 is a diagram illustrating a transporting system according to anexemplary embodiment of the present inventive concept.

Referring to FIG. 12, the transporting system 2 may not include acontroller 120 connected to first to fourth optical lines 21 to 24.Therefore, the first transporting unit 51 and the second transportingunit 52 may directly communicate with each other through the first tofourth optical lines 21 to 24.

For example, the first optical line 21 may be connected to the fourthoptical line 24 and the second optical line 22 may be connected to thethird optical line 23. If the first transporting unit 51 supplies afirst travel signal 62 through the first optical line 21 while enteringa second region, the first travel signal 62 may be emitted to a fourthregion 14 through the fourth optical line 24. Conversely, if the secondtransporting unit 52 supplies a second travel signal 65 through thethird optical line 23 while entering the fourth region 14, the secondtravel signal 65 may be emitted to the second region 12 through thesecond optical line 22.

When the controller (e.g., the controller 200 illustrated in FIG. 2)included in the first and second transporting units 51 and 52 issupplied with a travel signal from another transporting unit, it maymake the first and second transporting units 51 and 52 stop traveling.

While the present inventive concept has been particularly shown anddescribed with reference to exemplary embodiments thereof, it will beunderstood by those of ordinary skill in the art that various changes inform and details may be made therein without departing from the spiritand scope of the present inventive concept as defined by the followingclaims.

What is claimed is:
 1. A transporting system comprising: a first railincluding a first region and a second region, the first region being aregion where the first rail extends linearly and the second region beinga region where the first rail is curved; a second rail including a thirdregion, separated from the first region, and a fourth region overlappingthe second region, wherein the first and second rails merge at a joininglocation that includes the second region and the fourth region; opticallines disposed in the second region and the fourth region, wherein theoptical lines are parallel to each other in the fourth region; a firsttransporting unit traveling on the first rail; a second transportingunit traveling on the second rail; and a first controller controllingthe traveling of the first and second transporting units using lighttransmitted or received through the optical lines.
 2. The transportingsystem of claim 1, wherein the optical lines include first and secondoptical lines disposed along the third region and separated from eachother, and third and fourth optical lines disposed along the fourthregion and separated from each other.
 3. The transporting system ofclaim 2, wherein when the first transporting unit enters the secondregion at a first time and the second transporting unit enters thefourth region at a second time later than the first time, the firstcontroller supplies the third optical line with a stop signal.
 4. Thetransporting system of claim 3, further comprising a third transportingunit traveling on the first rail, wherein when the third transportingunit enters the second region at a third time between the first time andthe second time, wherein the first controller supplies the third opticalline with the stop signal until the third transporting unit exits thesecond region.
 5. The transporting system of claim 2, wherein the firsttransporting unit supplies the first controller with a first entrancesignal through the second optical line when it enters the second region,and the second transporting unit supplies the first controller with asecond entrance signal through the fourth optical line when it entersthe fourth region.
 6. The transporting system of claim 5, wherein beforesupplying the first controller with the first and second entrancesignals, the first transporting unit supplies the first controller witha first reference signal to be synchronized with the first controllerand the second transporting unit supplies the first controller with asecond reference signal to be synchronized with the first controller. 7.The transporting system of claim 6, wherein when the first and secondentrance signals are simultaneously supplied, the first controllersimultaneously supplies the first and third optical lines with a stopsignal and controls the first and second transporting units tosequentially resume traveling.
 8. The transporting system of claim 2,wherein the first controller comprises: a first interface boardconnected to the first and second optical lines; and a second interfaceboard connected to the third and fourth optical lines, wherein the firstinterface board includes a first transmitting unit supplying the firstoptical line with an optical signal and a first receiving unit receivingan optical signal supplied from the second optical line, and the secondinterface board includes a second transmitting unit supplying the thirdoptical line with an optical signal and a second receiving unitreceiving an optical signal supplied from the fourth optical line. 9.The transporting system of claim 1, wherein the first transporting unitincludes a second controller disposed in the first transporting unit andthe second transporting unit includes a third controller disposed in thesecond transporting unit.
 10. The transporting system of claim 9,wherein the optical lines include a first optical line disposed alongthe second region and a second optical line disposed along the fourthregion, and the second controller supplies the first optical line with afirst travel signal when the first transporting unit enters the secondregion.
 11. The transporting system of claim 10, wherein when the thirdcontroller enters the fourth region, the third controller determineswhether the second transporting unit travels in the fourth region basedon whether the first travel signal is received.
 12. The transportingsystem of claim 1, wherein each of the first and second transportingunits includes a transmitting unit and a receiving unit which overlapsthe optical lines.
 13. The transporting system of claim 12, furthercomprising a cover disposed on the optical lines, wherein the coverfaces the transmitting unit and the receiving unit of the firsttransporting unit, wherein the cover reflects a first optical signalemitted from the transmitting unit of the first transporting unit onto asurface of a first optical line of the optical lines disposed betweenthe cover and the transmitting unit of the first transporting unit. 14.A transporting unit comprising: a support unit supporting a targetobject; a driving unit generating a driving force to transport thetarget object; a receiving unit receiving a first optical signal emittedfrom a surface of a first optical line; a transmitting unit emitting asecond optical signal onto a surface of a second optical line that isspaced apart from the first optical line; and a controller controllingthe driving unit using the first and second optical signals.
 15. Thetransporting unit of claim 14, wherein the first optical line and thereceiving unit overlap each other, and the second optical line and thetransmitting unit overlap each other.
 16. A transporting systemcomprising: a first rail having a first region and a second region; asecond rail having a third region and a fourth region, wherein thesecond and fourth regions overlap each other, and the first and secondrails merge at a joining location that is within the second and fourthregions; a first transporting unit configured to travel on the firstrail; a second transporting unit configured to travel on the secondrail; a first optical line and a second optical line disposed within thesecond region; a third optical line and a fourth optical line disposedwithin the fourth region; and a first controller connected to the first,second, third, and fourth optical lines, wherein the first controller isconfigured to control the traveling of the first and second transportingunits at the joining location through the first, second, third, andfourth optical lines.
 17. The transporting system of claim 16, whereinthe first and second transporting units travel through the joininglocation at different times.
 18. The transporting system of claim 16,wherein the first controller communicates with the first transportingunit through the first and second optical lines, and the firstcontroller communicates with the second transporting unit through thethird and fourth optical lines.
 19. The transporting system of claim 18,wherein, when the second transporting unit enters the joining locationat a first time and the first transporting unit enters the joininglocation at a second time later than the first time, the secondtransporting unit travels through the joining location first, and thefirst transporting unit is supplied by the first controller with a stopsignal through the first optical line while the second transporting unitpasses through the joining location, wherein the first transportingsystem does not travel through the joining location while being suppliedwith the stop signal.
 20. The transporting system of claim 19, wherein,after the second transporting unit exits the joining location, the firstcontroller stops supplying the first transporting unit with the stopsignal, and the first transporting unit begins traveling through thejoining location.